Pressure gauge



Patented Mar. 17, 1925. y

y tarn PAE per a y ELTA L. RYAN, DE PITTSBURGH, PENNSYL'VMHA, ASS., QR t'll* blliL-Zlrdll'lii t'l WILLAMI J'. ARTZ, OF PITTSBURGH, PENNSYLVMWA rnnssunn eration.

Application led March 3, 1924. Serial No. (wal/QR To all 'whom 'it may concern:

Be it known that I, ALvA L. RYAN, a citizen of the United States, residing at Pittsburgli, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Pressure Gauges, of which the following is a specification.

This invention relates to pressure gauges and more in particular to tire-pressure gauges.

One of the principal objects of this invention is to provide a tire pressure gauge which will indicate the pressure of air forced into a tire. Another important object of this invention is to provide a pressure gauge which will automatically cut oil the air supply after'a desired pressure has been attained within the tire. A further object is to provide a pressure gauge which can be permanently adjusted, within its limits of operation, to cut oil' the air supply upon reaching a predetermined pressure in the tire. Still another object is to provide a. pressure gauge which is positive in action, compact and which can be manufactured at relatively low cost. Additional features and advantages of this invention will appear from the following description considered in connection with the accompanying drawings in which- Fig. l represents a longitudinal cross-sec.- tion, greatly enlarged, of the automatic tire pressure gauge.

Fig. 2 is a cross-section taken substantially on line 2-2 in Fig. 1.

Reference being had toy the drawing, the preferred construction comprises a gauge body l, open at the top and having a bottom 2 provided with a central hollow shank 3 the lower end of which has a suitably threaded portion 4l to accommodate a cou-.

4pling 5 by means of whichis secured the flanged union member 6 centrally drilled and properly threaded to be connected to the usual intlating. valve (not shown) with which all pneumatic tires are furnished. Suitable gaskets 7 and 8 are also used to inl sure leak-proof connections.

The inside of the gauge body is threaded lsubstantially down to the bottom, as indi-` cated by numeral 9, said thread being en. gaged by the outward thread 10 on the lower ort-ion ll of the pressure adjusting sleeve 2, the upper end 13 of which is open. and

slightly reduced in diameter to torni a. guiding and limiting ine-ans :tor the tubular pressure indicator cap la. l

Positioned within the indica-ter cap 141 is a calibrated coiled wire spring l5 inside ot which is an expansible tube 16 closed at the top and having an outside lange l? at its open lower end, said expansible tube being preferably made of very resilient rubber. The lower end of the spring 15in secured to the adjusting sleeve l2, near the bottom thereof, by means of an outwardly threaded ring 18 which engages the inward'threads 19 cut in said adjusting sleeve. This ring is part-ly counterbored to provide seat 2G for the spring and. bas` a, colla, 2l. which is pressedaround the lower turns oi" the spring, thus securely holding them..

The flange oi the rubber tube lll is clamped between the dat botto-in et' tbering 18 and a loose ring 22 which `is pressed against the flange. by means or" an outwardly threaded nut 23, also eng-aging the inside thread or' the adjustinf sleeve. 'llo facilitate the application of sait nut, suitable slot-s or notches 24- arc out in the base thereof for in sorting a flat screw driver or similar too-l. As shown in Fig. l, an intermediate disc 25, preferably of a composition of rubber and. fabrickis inserted next to the flange ot the, rubber tube to increase the thickness et said flange and take up the weer thereof.

The automatic closing mechanism et this pressure gauge comprises an inlet tribe se cured centrally in the betteln 2 ot the gauge body and communicating with the inlet aperture 27 provided therein.. The top ot the inlet tube is partly closed and is inwardly shaped to form the valve seat 28. rllie length ot' the inlet tube is such that it will at all times protrude within the rubber tube and its diameter is only slightly' less tlrln the sizeof the central aperturesftl and 30 provided respectively in the nut and 'loose ring 22; thus insuring the inlet tube against distortion due to hard shocks or abuse. To allow greater space for the passage of air into the tube 1 6, two or more sides of the inlet tube may be lattened, as shown by the numeral 43, in Fig.

Freely mounted 'for longitudinal morcment within the inlet tube is the properly lshaped valve disc il Y, the stein 32 ot which passes through a somewhat larger aperture provided inthe top ot said tube.

Said stem must be of very definite length (for a purpose to be stated later) and passes through a special thimble 34 secured in the top of the coil spring and through the top 35 of' the indicator' cap 14A Its outer end is also provided with screw threads 36 on which is secured an acorn-shaped nut 37. Bearing against the underside of the tubetop 38 is a disc 39 securely mounted on the valve stem. lt will thus be seen that, once the acorn-nut is applied, the indicator cap` will follow the outward and inward movements of the coil spring and rubber tube.

The air from the supply source is introduced into the gauge and tire through the outwardly threaded lateral pipe nipple 40 made integral with the gauge body. rlhis nipple is preferably drilled to two diameters 4l and 42, the latter being very much reduced in order to limit the sudden rush of too great a volume of air into the gauge.A Thisreduction is especially advisable when the supply of air is of ver much greater pressure than the one required within the tire. lVhen not in use, the nipple is sealed by means of a standard tire valve-cap'44, too well known in the trade to require detailed description.

The outward longitudinal travel of the adjusting sleeve 12 within the gauge body is limited by means of the inwardly threaded ferrule which engages corresponding threads 46 cut on the gauge body. This ferrulc also presses upon a packing ring 47 bearing upon the beveled follower ring 48 which is made sufficiently resilient by having suitable slots 49 out around its circumference.

'By forcing the ferrule down upon the packing ring, the connection between the gauge body and the adj isting sleeve will be made leakd proof and he latter will also be locked in any l selected position.

poifthe indicator ca and the adjusting sleeve are placed oppositely marked scales 5() andl having reference to the air pres' sure withinA the tire.y

The mode of operation of this tire `gauge is as follows: Referring to Fig. 1 and assuming that an air pressure of slightly over lthirty pounds is to be charged into the tire,

the 'ler-rule 45 is first loosened a little to unlock the adjusting sleeve l2 and the latter is then screwed down into the gauge body until the scale 50 reads slightly above thirty pounds. The pipe union G is new' screwed onto the valve of the tire (not shown) to be inflated and the pipe nipple is then connected to an air supply hose; thev tire valveeap 44 having, of course, lirstbeen removed. As the air enters the gauge body. the pressure indicating cap ll, which up to'that time had been forced down tothe zei"\rf.::uli1ig by the coil spring', will now gradually rise until it reads slightly over thirty pounds l pressure, at which moment the valve disc 31. will bear against its seat 2S and interrupt the passage of air into the tire, said air having' heretofore passed through the aperture 38' into the inlet tube QG and thence into the tire. As stated before, the length of the inlet tube and the vulve stem must be definitely established in order to assure. the closing of the air supply into the tube when ever the pressure indicator cap indicates the pressure to which the adjusting sleeve has been' set. Slight adjustments of the valve may be obtained by means of the acorn-nut 37, owing to the resiliency of the top 38 of the expansive tube which can be compressed more or less by the disc 39.

The device may also be used like an ordinary tire pressure gauge, it is, (independently of the air supply line) to indicate the pressure prevailing in a tire. To do this,

.the tire cap 44 is left on the pipe nipple 40 and the adjusting sleeve is screwed into the gauge body' down to a pressure greater than the one expected in the tire. The gauge is then applied to the tire valve and the pressurein the tire will be indicated directly by the scale on the indicator cap 14.

Also, should the operator wish to introduce a greater pressure than the one he had first intended to use and for which he has already Vset the adjusting sleeve, he ma do so by simply pushing the indicator cap own with his thumb until the tire has been blown up to his satisfaction, as ascertained by feeling the tire.

Although the primary intention of this invention is to provide a gauge especially adapted for inflating pneumatic tires7 it is evident that the same device could be made to suit other applications where fluid pressures are to be measured. It will be understood, of course, that the arrangement I have herein shown and described is susceptible of many slight changes in construction and disposition of the detail parts without departing from thc field and scope of the same, and I intend to include all such variations as fall within' the scopejof the appended claims, in this application in which the preferred form of my invention has been disclosed.

lll/'hat I claim is:

1. A pressure gauge comprising a gauge body; connecting means to a supply of iuid pressure; connecting means to a pressure receiving container an adjustable sleeve longitudinally movable Within said gauge body; a ressure -indicator movable Within said adjustable sleeve; an air inlet tube secured to and Within said gauge body and adapted to communicate with said receiving container; a valve seat provided within said inlet tube andat the upper end thereof, and a valve member secured tosaid pressure indicator and movable within said inlet tube for engagement with said valve seat.

I. pressure gauge comprisnc noso,

a gauge bo le; connecting means to a supply of fluid gg. eure; connecting means to e, pressure' and a. valve member secu ed to said pressure f indicator and movable Witlnn said inlet tube .for engagement with said valve seat.

3. A pressure gauge comprising a auge body; connecting means ,to a suppy of Huid pressure; connecting means to a pressure receiving container; an adjustable Asleeve longitudinally movable within said gauge body; a `pressure indicator-*movable within said adjustable sleeve; an air inlet tube secured to and Within said gouge body and adopted to communicate with said receiving continuer; a. vulve sont provided Within said inlet tubeand at the upper end av auge y thereof; u valve member secured to said -.body; connecting means to a suppy otgluld pressure indicutoriand movable Within said pressure; connecting means to a pressure reinlet tube 'for engagement-with said valve seat, and means :tor longitudinally adjusting the position ci? valve member within said inlettube,

4T A pres nge coinrisinv a hrau e body; connec cans djsupplv oibfluiid pressure; cui *ing moons to e pressure receiving co. einer; un sd'justable sleeve' longitudinally movable ,witbin said gauge body; means to loolrseid adjustable sleeve into any selected position viitbin suirl gauge body; a graduated scale positioned upon said adjustable sleeve; a pressnxfe indicator movable `wil-,bin said adjustable sleeve and having a graduated scale tliereonarranfred to read in opposite direction to said? rst scale; an air inlet tube secured to within said gauge body and adapted to co .rnunicate 'witn seid receiving container; e. lvulve seat provided Within said inlet tube id, at' tbe upper end thereof; a valve noemn comprising a valve disc and stem se` cured to said pressure indicator and movable within said inlet tube; saidinlet tube` and vulve disc being in such spaced longin oe3 B tudinal relation to causertbe engagement of said valve disc vvithsaid valve seat when said .pressure indicator registers tlie predee ternnned pressure set by sold adjusting sleeve.

5. A pressure gauge comprising a gang body, connecting means to a Supply of fund pressure; connecting means to a pressure receiving container; an adjustable sleeve longitudinally movable Within said gauge body; apressure indicator movable Within said adjustable sleeve; a calibrated coil Wire spring and an expansible tube positioned Wit-hin said pressure indicator and having cach one end secured thereto and the other endv secured to said adjustable sleeve; an air inlet tube secured tfr and within said gauge body and adapted to communicate with said receiving container' la valve Asont provided Within said inlet tube und at the upper end thereo'ta valve member ,secured to said pressure indicator and movable within said inlet tube for engagement with said valve seat; and means for longitudinally ad justing the position vof said valve member Within said inlet tube 6. A pressure gauge comprisi ceiving container; an adjustable sleeve longitudinally movable within said gauge body; a pressure indicator-movable withln said adjustable sleeve; a calibrated coiled wirespring und an expansible tube positioned within said pressure indicator and lieving euch one end secured thereto and the other end secured to said adjustable sleeve;

means to adjust said coiled Wire spring; an air inlet tube secured to and within said gauge body and adapted to communicate with saidy receiving container; a valve seat provided within said inlettube and at the upper end thereof; a valve membersecuured to`said pressure indicator and movable with-t. in said inlet tube "for engagement with sai valve seat; .means -for longitudinally adl justing the osition of said'valvemember within saidinlet tube, and outwardly o ery able means tolock said adjustable; sleeve into' znyl' selected position within said gauge ld testimony whereof II aix my. signature.

'ALVA L. RYAN.'

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